The present invention relates to teaching aids for trigonometric functions.
The six trigonometric functions have been taught for centuries by using teaching aids such as the chalkboard, charts, overhead projectors and other methods. Teachers need as many avenues and approaches as possible to communicate the meaning of the functions to students. There are no visual aids known to applicant, however, which illustrate the trigonometric functions by means of flashing lights.
Exemplary known apparatus are shown in the following U.S. Pat. Nos.:
2,509,301 Visual Aid for Trigonometry (Henry, Sr.) PA0 3,021,058 Mathematical Instruments (Horton) PA0 3,453,747 Sine Wave Generator (Saunders) PA0 3,826,021 Device for Demonstrating and Calculating Trigonometric Functions (De Andrea) PA0 3,827,163 Trigonometry Teaching Device (Grimes) PA0 4,435,162 Trigonometry Visualizers and Method of Making Same (Schoenwald) PA0 4,705,478 Superimposed Transparencies Used in Education (Djali).
U.S. Pat. No. 3,453,747 discloses a mechanically operated sine wave generator for visually demonstrating the algebraic addition of two or more sine waves having similar or dissimilar periods and amplitudes as a single undulating wave form. Sine wave motion may be imparted to a chalk stick by the mechanism, in which the algebraic addition of two or more waves may be shown.
U.S. Pat. No. 3,826,021 describes a device for demonstrating and calculating trigonometric functions. The device includes a planar member having a unit circle inscribed thereon and an angular scale associated with the circle to indicate the angle of an arc measured thereon. The planar member also has a vertically extending ordinate corridor defined by the ordinate axis and tangent line, and a horizontally extending abscissa corridor defined by the abscissa axis and cotangent line. A transparent cursor member having a radius vector hairline is pivotally mounted at the origin of the unit circle with the hairline passing through the origin and extending a length at least as great as that of the corridors, and is adapted to be pivotally moved through at least a 90 degree quadrant of the unit circle. The tangent, cotangent, secant and cosecant functions for a given angle may be demonstrated by visual observation of the hairline within the corridors at its points of intersection with the tangent and cotangent lines. The device can also include means for indicating the sine and cosine functions within the unit circle to permit the demonstration of all the trigonometric functions on one device.
U.S. Pat. No. 3,827,163 describes a trigonometry teaching device. It includes a platform, a rotatable transparent disc and a transparent slide member. The slide member moves linearly in response to disc rotation. Circular and linear scales are imprinted on the three parts.
U.S. Pat. No. 4,435,162 discloses a trigonometry visualizer which includes a pair of circular discs connected at their centers for relative rotation coaxially of one another. The upper disc has a large circle disposed coaxially of the common axis of the discs. The lower disc has on its face a smaller circle the diameter of which is one half that of the circle on the upper disc. The circle on the lower disc is radially offset from the axis of the discs by an amount equal to its radius so that it registers tangentially at one diametral side with the circle on the upper disc, and at its opposite side with the common axis of the discs. A pointer on the periphery of the lower disc is viewable through the upper disc, and when the discs are rotated relative to each other, registers selectively with a plurality of graduations on the upper disc which divide the large circle into its degree values.
U.S. Pat. No. 2,509,301 describes a visual study aid for trigonometry, which includes a disc member having a plurality of arcuate slots formed therein. A single block slides over one face of the disc, and a plurality of interconnected arms are journaled in the block and extend through the slots. The arms are positioned in selected angular relationships to each other on movement of the block relative to the disc member, one of the arms constituting a radius arm and being journaled at opposite ends in the block and disc member respectively. The other arms are each journaled at one end in the block and at the other end are pivotally connected to the first end of the radius arm.
U.S. Pat. No. 3,021,058 describes a mathematical instrument for indicating in one operation the six trigonometric functions of any given angle. It comprises a back member having thereupon scales indicating the angles and the values of their trigonometric functions. Rotatably mounted over the back member is an elongated vector operable to correlate the angles and the values of the functions. In order to correlate completely the angles with all of the functions, an intersector member is pivotally attached to the vector and cooperates therewith in such fashion that by a single setting of the vector to the desired angle, all six trigonometric functions of the angle may be read from the vector and intersector positions.
U.S. Pat. No. 4,705,478 describes superimposed transparencies used in demonstrating geometrical relationships.